源自日本血吸虫的半胱氨酸蛋白酶抑制剂对葡聚糖硫酸钠诱导的小鼠溃疡性结肠炎的影响

Effect of cystatin from Schistosoma japonicum on DSS-induced ulcerative colitis in mice

目的探讨日本血吸虫半胱氨酸蛋白酶抑制剂(Schistosoma japonicum cysteine protease inhibitor,SjCystatin)对葡聚糖硫酸钠(Dextransulphate sodium,DSS)诱导的小鼠急性溃疡性结肠炎的抑制作用。方法 18只雌性C57BL/6小鼠随机分为3组:A组为对照组,B组为肠炎组,C组为SjCystatin治疗组。A组给予蒸馏水,B、C组连续饮用3%DSS溶液7 d诱发肠炎;C组每天经腹腔注射10μg SjCystatin,A和B组注射PBS。观察各组小鼠临床表现,进行临床疾病活动指数(Dis-ease activity index,DAI)评分。第7天处死小鼠,观察结肠大体及组织病理改变。同时提取小鼠结肠组织匀浆,采用酶联免疫吸附实验(ELISA)测定其上清中肿瘤坏死因子-α(TNF-α)、白细胞介素-4(IL-4)、IL-6及IL-10水平。结果与A组([0.50±0.28)分]相比,B组小鼠DAI评分([9.30±1.30)分]明显增加,建模后小鼠结肠病理损伤显著,结肠组织匀浆上清中TNF-α为(321.33±67.01)pg/mL,IL-6为(403.58±180.51)pg/mL,均明显上升。C组小鼠DAI评分为(6.67±1.57)分,显著下降(F=86.86,P<0.01);小鼠结肠大体及组织病理明显缓解,结肠组织匀浆上清中TNF-α为(188.14±40.14)pg/mL,IL-6为(209.71±48.47)pg/mL,均显著下降(F=17.46、9.89,P<0.01)。结论 SjCystatin对DSS诱导的C57BL/6小鼠急性溃疡性结肠炎有抑制效果。

Objective To investigate the effect of cysteine protease inhibitor derived from Schistosoma japonicum（SjCystatin） on dextran sodium sulfate（DSS）-induced acute ulcerative colitis in mice. Methods Eighteen C57 BL/6 mice were randomly divided into three groups ： a control group treated with PBS（Group A）, a DSS-induced-colitis group treated with PBS（Group B）, and a DSS-induced-colitis group treated with SjCystatin（Group C）. Colitis was induced in mice by giving 3% DSS orally for 7 days. During this period, the mice were daily injected with 10 μg of SjCystatin or PBS only as a control intraperitoneally. The mice were monitored daily for their clinical manifestations and given scores based on disease activity index（DAI）. The severity of colonic inflammation was monitored by the macroscopic score and pathological change. The cytokine profile including TNF-α, IL-4, IL-6 and IL-10 in the supernatants of colon homogenate was detected by ELISA. Results Compared with Group A（0.50 ± 0.28）, the DAI score increased significantly in Group B（9.30 ± 1.30）（F = 86.86, P 〈0.01）, with remarkable pathological damages seen in colon tissues. and the levels of TNF-α and IL-6 were（321.33±67.01） and（403.58 ±180.51） pg/mL.The DAI score significantly reduced in Group C（6.67±1.57） as compared to Group B（F= 86.86,P〈0.01）,with improvements in the macroscopic and microscopic pathology in mouse colon specimens. As compared to Group B, the levels of TNF-α[（188.14 ± 40.14） pg/mL] and IL-6 [（209.71 ± 48.47） pg/mL] significantly decreased（F = 17.46 and 9.89,both P0.01）.Conclusion SjCystatin has a significantly inhibitory effect for alleviating DSS-induced acute ulcerative colitis in C57 BL/6 mice.